Baker's yeast mediated reduction of substituted acenaphthenequinones: Regio-and enantioselective preparation of mono-hydroxyacenaphthenones

Baker's yeast mediated reduction of acenaphthenequinone within 4-10 h afforded mono-hydroxyacenaphthenone mainly with low enantioselectivity, the substrate and mono-hydroxyacenaphthenone product almost converted to dihydroxyacenaphthene after 48 h. By control of the reaction time and in the presence of DMF as co-solvent, the reduction of 6-substituted acenaphthenequinones under vigorous agitation afforded the corresponding 2-hydroxyacenaphthenones in 24-84% yields with 10-93% ee.

Bioreduction of quinone derivatives by immobilized Baker's yeast in hexane

Immobilization techniques and biocatalytic transformations performed in organic media are new developing methods for organic reactions. Baker's yeast was immobilized on the alginate supports. This preparation contained about 20% of dry yeast cells. The immobilized Baker's yeast were found to be very effective in the reduction of o-benzoquinone, p-benzoquinones, naphthoquinones, and anthraquinones in hexane.

Regio-and Stereo-selective Bioreduction of Diketo-n-butylphosphonate by Baker's Yeast

A regio- and stereo-selective reduction of diketo-n-butylphosphonates by baker's yeast was reported. The chemical yield and ee value of these reactions are highly dependent on the structure of substrates. The resulting optical active hydroxy^alkanephosphonates can be used as chirons for the synthesis of polyfunctional organophosphorus compounds. As useful building block, a series of α,β-unsaturated ketones bearing chiral hydroxy group in addition to trifluoromethyl moiety was prepared via the Horner-Wadsworth-Emmons (HWE) reaction of the biotransformation products.

Saccharomyces cerevisiae in neuroscience:how unicellular organism helps to better understand prion protein?

The baker's yeast Saccharomyces(S.)cerevisiae is a single-celled eukaryotic model organism widely used in research on life sciences.Being a unicellular organism,S.cerevisiae has some evident limitations in application to neuroscience.However,yeast prions are extensively studied and they are known to share some hallmarks with mammalian prion protein or other amyloidogenic proteins found in the pathogenesis of Alzheimer's,Parkinson's,or Huntington's diseases.Therefore,the yeast S.cerevisiae has been widely used for basic research on aggregation properties of proteins in cellulo and on their propagation.Recently,a yeast-based study revealed that some regions of mammalian prion protein and amyloidβ1–42 are capable of induction and propagation of yeast prions.It is one of the examples showing that evolutionarily distant organisms share common mechanisms underlying the structural conversion of prion proteins making yeast cells a useful system for studying mammalian prion protein.S.cerevisiae has also been used to design novel screening systems for anti-prion compounds from chemical libraries.Yeastbased assays are cheap in maintenance and safe for the researcher,making them a very good choice to perform preliminary screening before further characterization in systems engaging mammalian cells infected with prions.In this review,not only classical red/white colony assay but also yeast-based screening assays developed during last year are discussed.Computational analysis and research carried out using yeast prions force us to expect that prions are widely present in nature.Indeed,the last few years brought us several examples indicating that the mammalian prion protein is no more peculiar protein–it seems that a better understanding of prion proteins nature-wide may aid us with the treatment of prion diseases and other amyloid-related medical conditions.